In the art of shingle manufacture, it has become commonplace to construct shingles from a base mat, generally having an asphaltic composition applied over the mat, following which granules are applied to the shingle, in various configurations. The art has developed such that the granule applications, shingle thicknesses, overlainments of shingle materials, etc. have simulated the appearance of shingles of natural roofing materials, such as slate or wood. Often, such natural roofing materials such as slate or wood have greater exposures than asphalt shingles.
Standard asphalt shingles have a five inch height exposure in the installed condition, and a tab width (as measured across the bottom of a shingle tab) of 12 inches. This gives an exposure height to width ratio of about 0.417, often appearing to be unnatural relative to slate or wood shingles.
Also, the ordinary 12 inch high shingle designed to have 5 inches of height exposure will allow the manufacture of 300 shingles each 36 inches in overall width by 12 inches in height, out of 300 linear feet of shingle membrane or rolled material, when manufactured on a 36' wide mat.
Additionally, these standard shingles of 12 inches in height having 5 inch exposure will ordinarily require 80 shingles per roofing square (100 square feet of roof area) installed, and will utilize 320 nails per square when three-tabbed shingles are installed, and 400 nails per square when four-tabbed shingles are installed.